Most CIS subcontractors overpay tax every year. 123Tax handles your CIS returns, your MTD submissions, and your tax refund claim — all through WhatsApp.
The basics
CIS stands for the Construction Industry Scheme. If you work as a subcontractor for a contractor in construction — whether you're a bricklayer, plumber, electrician, roofer, plasterer, or labourer — your contractor is required by HMRC to deduct tax from your pay before you receive it.
That deduction is usually 20% of your labour costs (or 30% if you're not registered with HMRC for CIS). The contractor sends that money straight to HMRC on your behalf. You get paid what's left.
The problem? Those flat-rate deductions often take more tax than you actually owe — especially once your allowable expenses are factored in. That means you could be owed a refund at the end of the year, and most subcontractors never claim it.
The opportunity
When your contractor deducts 20% (or 30% if you're unverified) from your pay, they're taking a flat percentage — regardless of your actual tax position. Once your personal allowance and allowable expenses are taken into account, you've often paid HMRC more than you owe. That overpayment is yours to claim back.
Worked Example
Subcontractor earning £45,000/year
These example figures are illustrative. Your actual refund will depend on your individual circumstances.
What we do
Whether you're a chippy, a sparky, or a roofer — if you're on CIS, we handle the lot. No software. No spreadsheets. Just WhatsApp us and we take care of the rest.
Tracks your CIS deductions
We keep a running record of every CIS deduction taken from your pay throughout the year.
Calculates allowable expenses
Tools, fuel, PPE, workwear, phone costs, van costs — we make sure every legitimate expense is counted.
Files your Self Assessment
At year end, we prepare and submit your Self Assessment tax return to HMRC on your behalf.
Submits quarterly MTD updates
Making Tax Digital means quarterly submissions are now required. We handle every one of them for you.
Claims your CIS tax refund
If you've overpaid tax through CIS deductions, we claim the money back from HMRC on your behalf.
Allowable expenses
Every legitimate expense reduces your taxable profit — and increases the size of your refund. Here's what most plumbers, sparks, bricklayers, and roofers can claim.
Tools & Equipment
Drills, saws, hand tools, power tools, and specialist equipment for your trade.
Work Clothing & PPE
Steel-toe boots, hi-vis vests, hard hats, gloves, overalls, and branded workwear.
Vehicle Costs
Mileage (45p per mile for the first 10,000) or actual running costs for your van or car.
Fuel
Diesel, petrol, or electricity for your work vehicle — journeys between sites and to suppliers.
Phone Bills
The business-use portion of your mobile phone bill — calls to contractors, suppliers, and clients.
Materials
Any materials you've bought for a job that weren't reimbursed by your contractor.
Training Courses
CSCS card renewals, gas safety courses, Part P electrical courses, and any training directly related to your trade.
Real stories
"Got a £1,800 CIS refund I didn't even know I was owed. These lot know the construction game inside out. Best money I've ever spent."
Mike
Plumber, Birmingham
"Been on CIS for 12 years and never claimed my overpayment back. 123Tax sorted it in weeks. Absolute game-changer for anyone on the tools."
Gary
Roofer, Newcastle
Stop leaving money on the table. Whether you're a plumber, bricklayer, electrician, roofer, or labourer — if you're on CIS, we'll handle your returns and claim back what you're owed.
No credit card required. No app to download. Cancel anytime.